Hello! First of all, sorry for my english. I have a problem with MikroTik SXT Lite5 (RB SXT5nDr2), it just a stopped working - no connection to LAN/WLAN, no beeps, no flashes, anything but power LED and three "signal" LED's. It has no reaction to "RESET" button, NETINSTALL mode doesn't work at all, device completely dead. I replaced the CPU with help of BGA rework station and nothing changes, but after i reflash the 25-series FLASH chip with firmware from another mikrotik device (same model), it works! All functioning fine, but my license key was broken. Ill decided to try "repair" bricked firmware with help of working flash image, and eventually license key not work. Winbox tell's me "Your router does not have any valid key". Any chances to recover my device's firmware? I attached my broken rom, modded rom and working rom from another device. Please, help me!

Have You tried boot Your device with backup booter before actions with the chip?

I don't think anyone in this forum can help you. You need the right license key for board's Software ID (you can see it in System->License). And if it works like in x86 version (where it depends on disk, I think model, serial number or both, plus some possibly random stuff on the beginning of disk), it's likely that your repair changed some of it and you now have different Software ID. And of course no key for it.

You can try if "Upgrade/Get New Key..." in License window does something. Or check if you by any chance copied Software ID from other device, in that case you could take the key from there.

If nothing works, try writing to support, if they can help you. If I was in their place, I'd give you new key. If not for anything else, then just because I'd fear that you might continue in your quest and eventually crack the license algorithm.

Have You tried boot Your device with backup booter before actions with the chip?

I've tried this methods: As i said before, "USER LED" no lit, no flash, anything. Serial console method i'm not tried, but i think it doesn't work, because i'm not seen any signal pulses on "E-JTAG" and "UART" testpoints. Maybe i need initiate the connection? If anyone knows, tell me please how it should work, then i solder cable. It's so bad, i dont know previous software ID (when device worked), my ID changed or no... That's info from my modded ROM: At this time i don't have NAND-flash programmer, and i can't monitor any differences on chip's contains. Maybe i broke the license, when insert another ROM firmware and now it permanently changed my software ID? Thanks for replies!

Seriously, mail to MikroTik support and ask if they can help you (give you new key). You bought the device with license, device broke, you repaired it, helping you to revive license would be fair, I think. It would definitely save you a lot of work. Save alternative approaches in case they refuse (although I don't think you have much chance to succeed, you'd be basically hacking the device).

License can be lost only for two reasons:
1) Downgrade below minimal supported RouterOS version (upgrade will fix it);
2) Device has been modified on hardware level in improper way which avoids any kind of warranty and in such cases new key will not be provided.

I replaced the CPU with help of BGA rework station

Why not submit for warranty instead? CPU change is not possible, the units are locked to specific CPU.

Hi,

I have the same issue with a similar model , do you think if I refresh the 25 series chip with a firmware from another device then I will face the same issue with the license ?

yes, if you will have license problem if you completely replace flash chip. License is probably locked to some CPU ID or other HW ID.
It might be possible to read contents from the bad chip and copy over the hardware information block (with MAC addresses and other stuff, probably some license stuff there too).
If you diff the dumps of flash from few devices, you will see what parts of flash are always the same and what changes. The changing part needs to be preserved as it's device specific.

Or you can just buy a license...

On SXT devices, license stored in both nand and 25-flash chip, on boards with only one flash memory chip, license stored in flash and OTP-area of that flash chip. Any modifications of code will cause a license failure. License isn't CPU specific, i've replaced over few hundreds SoC (AR724*, AR9344-*) without any hardware or firmware modifications and all works fine. So, most simplier way to repair sofware problems is cloning both chips, but in result you'll been have absolutely identical devices (MAC's and serials). Another way to repair - edit 25-flash dump. In most cases problem hide in ~ first kilobyte of data, you'll need to know what version of routerboot on your dead device and insert the piece of code from the same version of working dump. After that, in most cases device will react on reset button and you can reflash it in a normal way via netinstall. So sad that mikrotik support is oriented for sales, not for support at what it must be. All of my support tickets ended the same way - RMA or buy the new one.

Is it fair to attack Mikrotik support because you repaired a device yourself and now it doesn’t work? I’m not sure how warranty works in the Ukraine but in the UK the moment you significantly modify a device the warranty and support on it is invalidated.

If the device was still under warranty you should have sent it back to Mikrotik for repair or replacement.

If you repaired the device because it wasn’t under warranty anymore then I think you can’t attack Mikrotik support if they won’t help you do something you’re not supposed to do.

Of course it also depends on the age of the device and to the ratio of average income to the price of such devices.
Frankly, when I had a single SXT Lite5 fail after a couple of years and see what they cost new, I would just bin it.
When "hundreds of devices" are affected it could be different.

Here. stuff usually fails due to moisture. It appears that many manufacturers of outdoor equipment do not pay enough attention
to that. Screws and brackets rust, water and insects get into equipment and cause leakage currents eating away traces and connectors, etc.
So after a couple of years we just have to buy something new. But usually that means new technology, with more performance at lower price.

The challenge for most users now is they don’t appreciate the value in the RouterOS licence. The licence is part of the value of the device. It has a cost. Repairing the hardware is fine, and I don’t see any reason why someone shouldn’t repair their own hardware. The software is (and always will be) the property of Mikrotik and if they don’t want to re-issue a licence for an SXT that appears to be repaired from 2 broken SXTs then I think you have to respect that decision.

The cost of license is completely arbitrary. To ilustrate, regular price of L4 license is $45, but at the same time hAP mini, complete hardware with L4 license included, is $19.95. So what's the cost of license there? It's more like free bonus. It's the most extreme example, but it's clear that even with SXTs and other not too expensive devices, the cost of license is not $45.

But more importantly, look at it from customer perspective. You buy the whole package, functioning device. If it breaks and it happens soon, there's warranty and you can get replacement from seller. But if it breaks later, but still too soon, meaning that as customer you really expect the thing to survive longer than warranty is (it's usually not very long), then what?

If it's something like infamous RB4xx capacitors, you can spend a little bit of money, time and some curse words directed at MikroTik's quality control, but in the end you have functioning device again and you can be happy. But if the problem is with another component, you repair it, the hardware is perfectly fine, but you're stopped by software, it's doesn't feel good. Even if it's not MikroTik's fault like capacitors were, perhaps something just burned because of power spike, it still sucks.

MikroTik has no obligation to give out replacement licenses for user-repaired devices, it would just be nice thing to do, make the company look more friendly. It could be worth few lost sales of new devices, it can't be that much.

The cost of license is completely arbitrary. To ilustrate, regular price of L4 license is $45, but at the same time hAP mini, complete hardware with L4 license included, is $19.95. So what's the cost of license there? It's more like free bonus. It's the most extreme example, but it's clear that even with SXTs and other not too expensive devices, the cost of license is not $45.

The cost is not the same thing as the price! The (incremental) cost of the license is obviously zero. It costs a certain (high) amount of money to develop the software and this cost has to be recouped over all the sold units, but it does not cost more to have another unit running the same software.
Otoh there is the price of the unit in the market, it is not determined by the cost but by what the customer wants to pay. Preferably the price the customer pays is higher than the cost of the unit, or else the company will go out of business (at least when that is the situation across the entire product gamma).
Obviously MikroTik consider that those that want to buy individual licenses to run RouterOS on their own hardware or to extend the features of existing hardware are willing to pay a bit more than those that want to buy a toy access point. But I am a bit surprised that there is no L3->L4 upgrade license for like $15-$20 in addition to the standard $45 license that you could use to run a big border router on X86 hardware.
Similarly there could be a license for a price like that to fix an existing Routerboard product. But if course one always has to move carefully or else the market will be flooded with clones of existing MikroTik products that have a little more margin (like the 4011) and it will be advertised with "just obtain a 'replacement license' at MikroTik for $15" or so. The $45 license price guards this a little more.

About upgrades, from MikroTik's FAQ:

Just like you can't easily upgrade your car's engine from 2L to 4L just by paying the difference, you can't switch license levels as easily.

Of course with cars there's a reason for that, because you can't change engines with few mouse clicks.

And for repairs, someone could bring up the eco-aspect, right to repair and stuff. It's certainly not very "green" to throw perfectly functioning device in trash. And even if the customer has a choice to buy new license, it doesn't sound very fair, to have to pay for the same thing again, unless there's a major discount (only small price to pay someone at MikroTik who would handle the replacements). But since I'm not hardcore eco-warrior myself, I'll leave that to someone else.

The problem with hardware clones is possible, but I'd deal with that when/if it happens.